On 2014년 07월 09일 18:23, Daniel Vetter wrote: > On Tue, Jul 8, 2014 at 6:20 PM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote: >> 2014-07-08 22:37 GMT+09:00 Daniel Vetter <daniel@xxxxxxxx>: >>> On Wed, Jul 02, 2014 at 11:25:19AM -0400, Jerome Glisse wrote: >>>> Anyway as this is upstream i guess you can keep it. This is just an horrible >>>> API that allow to circumvant any limit set by memcg for page locking and all. >>>> But anyway GPU driver never played in the same ballpark as other driver. >>> >>> I agree that exynos userptr as-is should be removed since as opposed to >>> the i915 implementation it doesn't play nice with the core mm >> >> Can you give me more details why you think so? > >>From a very quick look there's two pieces: > - The implementation with the vma tricks looks _really_ scary. You'd > need to have Al Viro's opinion on it though. You mean that it checks VM_DONTCOPY flag before copying vma? If so, I really forgot it. > - If I'm reading the code correctly userspace can pin unlimted amounts > of memory, but I've gotten a bit lost in the code. In i915 we have Not so. g2d driver is checking if user-requested buffer size is more than maximum capacity of g2d dma. So it can never pin unlimited amounts of memory. > shrinkers and mmu notifier to make sure that if the vm needs this > memory again we'll make it available. I am not familiar to mmu notifier. I will look into how i915 driver handle it. Thanks for comments, Inki Dae > -Daniel > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
